Artificial shelters enhance the establishment of the aphidophagous predator Scymnus interruptus on sweet pepper plants

The success of biological control programs often depends on the establishment of natural enemies in or around the crop. An emerging strategy that aims to improve establishment is through the provision of niches that act as shelters. These shelters can enhance the natural enemies' effectiveness by providing: a suitable microclimate; protection against other predators or pesticides; and/or alternative food. Generally, shelters are natural habitats such as flower strips, intercropped areas, hedgerows, or banker plants. The use of artificial devices as shelters remains underexplored. In this study, we assessed the functionality of an artificial shelter for the aphidophagous predator, Scymnus interruptus Goeze (Coleoptera: Coccinellidae). A tailor-made artificial shelter for oviposition was developed and tested in both laboratory and greenhouse conditions. Our results showed that S. interruptus females strongly preferred to use the shelters as an oviposition site compared with sweet pepper (Capsicum annuum L.) leaf discs supporting the aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), its primary prey. Furthermore, S. interruptus oviposition rate was doubled when shelters were supplied. In a greenhouse experiment, population densities of S. interruptus larvae increased twofold when shelters were provided. Additionally, providing artificial shelters in a sweet pepper crop has the potential to enhance aphid control and could also be a valuable method for monitoring predator densities in the crop.

Automated summary

The success of biological control programs relies on establishing natural enemies in or around crops. One strategy to improve establishment is by providing niches as shelters, which can enhance effectiveness by providing appropriate microclimates, protection, and alternative food. While shelters are typically natural habitats like flower strips or hedgerows, the use of artificial devices remains underexplored.